In recent years, small scale and light electronic devices with multi-functionality and high functionality are becoming widespread and a greater level of integration of installed electronic components is being demanded. In response to such demands, the number of each type of electronic component being manufactured as a semiconductor device is increasing. Consequently, small scale and light electronic devices such as a sensor etc. for detecting dynamic quantity are being manufactured using semiconductor devices apart from semiconductor devices manufactured as circuit components. For example, a moving part which displaces according an external force is formed on a semiconductor substrate and a sensor which detects the displacement of this moving part using a piezo resistor element or capacitance sensor element is realized in an acceleration sensor having a small scale and simple structure using MEMS (Micro Electro Mechanical Systems) technology.
In addition, conventionally, a sensor which detects vibration according to the presence of a contact between a movable electrode and a fixed electrode formed on a semiconductor substrate is known as a contact type semiconductor sensor (for example, refer to patent document 1). Alternatively, a sensor is known in which a ring shaped movable electrode is formed on an exterior spiral part of a structure in which the movable electrode is wound a plurality of times in a spiral shape around a fixed part on the semiconductor substrate, and which detects tilt by the presence of a contact between the movable electrode and a fixed electrode which is arranged on the spiral of the movable electrode (for example refer to non patent document 1).    Patent Document 1: Japanese Laid Open Patent 2007-303974    Non Patent Document 1: Yasushiro Nishioka, and 5 others, “MEMS Tilt Sensor Fabricated Utilizing Anodic Bonding of Thin Silicon Film on Glass Substrate” Journal of Electronics E, Volume 129, No. 10, 2009, p. 328-332.
However, a contact type semiconductor sensor proposed by the patent document 1 and non patent document 1 stated above cannot detect the presence of a contact between a movable electrode and a fixed electrode, and because an output level of an electrical signal generated when the movable electrode and fixed electrode contact is small, an amplification circuit etc. for amplifying this electrical signal was required to be arranged on the exterior of the sensor. In addition, the direction of the external force detected is also limited.
Furthermore, the manufacturing processes in a sensor which detects dynamic quantity using a conventional piezo resistor element or a capacitance type semiconductor sensor are complex and manufacturing costs increase.
The present invention attempts to solve the above problems by providing a dynamic quantity sensor and manufacturing method thereof which can detect the magnitude, direction and acceleration of an external force and which can be manufactured at low cost.